The disclosure relates generally to methods and apparatus for enhancing images that are displayed on one or more displays, and more particularly to methods and apparatus that provide images that are displayed across multiple displays, video walls, and multi-view systems such as 3D, stereoscopic display systems, video walls, and other multi-view systems.
3D video that employs, for example, multi-view display operations such as stereo video that employs left and right eye views, or other multi-views taken from different perspectives of an object when displayed can provide an impressive 3D effect. 3D video systems are becoming an important part of home and public entertainment. Stereo display devices such as projectors, televisions, flat panels or computer systems may receive, for example, left and right eye stereo images and process them for display. A simple system may scale or color convert the images with no adaptive enhancements. In this case, processing of the left and right eye view frames (also includes fields) independently may not cause any significant image degradation. However, better quality display systems, such as televisions or computer displays with graphics processing units and/or host processors such as CPUs, may employ hardware based or software based video enhancements. (“Processors” also referred to herein as “processor cores” or “cores”.) These systems may do significant amounts of adaptive processing such as color enhancements, contrast enhancements, noise removal, edge enhancements, deinterlacing, edge adaptive scaling and other image enhancement operations in an attempt to improve actual or perceived image quality. Adaptive enhancements are not fixed—they change dynamically depending on the pixel values in a small area or over an entire image that is displayed. In a stereo image system, the left and right images may have large areas that are quite different, especially if there is a large stereo displaced foreground object. In this case, the temporal information used for enhancements may appear to be quite different for the left eye and right eye image. As used in this example, the temporal information refers to information taken from a single right eye or left eye image. Also the left and right eye images may be processed by different hardware components, whether GPU or CPU cores or even in different image devices altogether such as dual projectors.
If the enhancements of an object or area in the image are independent for each eye view, then the left and right eye frames may result in unintended image differences which can drastically reduce the quality of a 3D image. This may cause, for example, eye strain or headaches and can significantly reduce consumer appeal.
Also, where multiple displays are used to display a single logical frame (i.e., where each of the displays is controlled to display a portion of a logical frame) each display may output a portion of a larger logical frame and the corresponding graphics processor or processor cores that control one or more frames may not communicate enhancement information across multiple processors. Accordingly, poor image quality can result when a single display frame is displayed across multiple displays. For example, different portions of a logical frame may be processed by differing GPUs or CPUs. Each processor core may perform its own image processing for its respective portion of the logical frame that is displayed. For example, with a wall of multiple displays that display a single logical frame, each respective display may display output from one or more GPUs (for example, GPU cores). However, separate dynamic enhancement may be performed using different paths such that, for example, differing GPUs that provide image enhancement processes are not properly communicated (or not communicated at all) to the other GPUs that produce other color enhancements for other portions of the entire logical image.
It is also known to employ multiple graphics processor cores to output a single frame on a single display. For example, each processor core may process a portion of a checkerboard pattern, differing lines or other portions of an image single display. However, such implementations use another processor core (e.g., host) to determine image enhancement statistic information for a full frame. As such, the host processor core has to perform all of the statistics processing and the host processor core may not be at the appropriate portion in the overall image processing pipeline. Also, analyzing pixel data by the host can result in large amounts of bandwidth and processing inefficiencies.
Also, existing single image displays or stereo or multi-video wall installations are known to perform a video calibration using methods such as static video calibration techniques that set identical color temperature and brightness and gamma and contrast settings using, for example, external cameras or other techniques. These video calibration techniques however are typically static one time measurements and calibrations. They do not address issues of multiple images and displays that are slightly different but must still receive identical, coordinated image enhancements.
Accordingly, an improved video processing apparatus, system and methods are desirable.